My 535 now backs off the dock about 4 inches then proceeds to just goes in circles. Is this the circle dance I read about in here? I thought that was only happening to the 4xx models?! Anyone else with a 5xx that did that? How can I fix this behavior?

What may be happening on your 5XX model is that one of the wheel drive motors is not working. If your Roomba only spins in one direction all the time then it will be a failed drive motor. This cause is possibly debris inside the motor housing thus preventing the motor from operating. You might try and remove the wheel module, use some compressed air and blast the openings of the motor.

jenn wrote:My 535 now backs off the dock about 4 inches then proceeds to just goes in circles. Is this the circle dance I read about in here?

No, but "going in circles" is part of the circle dances.

I thought that was only happening to the 4xx models?!

That's good thinking, keep it up!

I'll provide some detailed info, but can't provide any useful repair advice which you could DIY.

It would be useful for you to have explained where about the 535 is pivoting -- viz., is it pivoting about a stalled drive-wheel, or is it pivoting about the robot's center?

I'll assume it to be the latter, otherwise you might have described the 535 as crashing into its Home Base while gyrating through large arcs. Any other behavioral data could also be useful -- such as does the fault appear EVERY time 535 leaves the dock?

You have fair assurance that both drive-wheel motors are functional, because both motors ran while reversing off the dock by "about 4 inches". That strongly suggests those wheel motors will both drive in the forward direction when commanded to do so (barring a faulty transistor-switch on the main-elex board). Following the back-off, the 535 spins through a large angle to select a forward-travel vector that will not intersect the HB.

My 535 then spins about body center through 180-degrees and then heads straight away from the HB.

It is the 180-degree spin which your 535 seems to be caught in. That would suggest your 535's fault to be associated with the wheel-turns counting process (the only way a robot can do a neat 180-deg spin is to accurately know that both wheels rotated through the same angle). These 5XX machines use a magnetic based rotation sensor (rather than the optical-based sensor that caused so much circle-dancing over all of Roomba's prior history) in the drive-wheel's module to generate rotation data which the machine's controller uses to keep track of wheel-speed and distance traveled. That magnetic system is immune to debris gathering on it!

Now that you know about the drive-wheel rotation sensor, I might point out that yours must have been working properly as Roomba reversed four inches away from the HB's dock! So what could have changed in the drive-wheel module between the reverse operation and engaging the 180-deg spin? Nothing I can imagine! You see? I have talked myself out of your 535 having any problem! Fault choices are not obvious.

How very, very odd?! This circling he will do is I've noticed "only" happening when started from the HB. When I hand carry him into another room and start him manually he will behave fine.

He appears to be confused on where to go when coming off the HB all of a sudden. After backing off a few inches he woll now circle in one spot... circles a few times left, stops then spins right..etc. I'm deaf but if I could hear I'd sweart he was saying, "Hhhmmm, which way should I go first.. this way... or this way?"

I've seen that behaviour when a 4th generation virtual wall is used with a 5XX model Roomba. Your Roomba may be over-reacting to the Home Base IR system. What is unknown is what unit is possibly at fault, either the home base or the IR receiver on the Roomba bumper. If under warranty contact IRobot for support.

My Roomba occasionally does the same thing. He backs off the base and then sits on the spot doing a slow turn, first one way, then the other. When picked up and placed clear of the base he proceeds to clean as normal. Is your homebase situated near to a reflective surface? In my case I suspect that the beam from the homebase is bouncing off the white surface of our dryer and the Roomba is in "stay away mode" and trying to avoid the homebase. For some reason he can't escape, maybe because he is registering two beams, one from the base and the fake one from the dryer. I think that our cat tray gets shifted slightly at times and this is when the beam is somehow re-directed to bounce off the dryer. This is all just a guess on my part though, I haven't tested my theory.

I just decided to test my theory. Sure enough, I pressed clean and the Roomba backed off the base and began to revolve on the spot. I switched it off and put it back on the base. Then I moved the cat tray along the wall an inch and tried again. This time Roomba backed off and went out on a mission. Hurrah!

Have a look near your homebase for something that may be interfering with the beam.

Sigh... now even upon hand carrying it into the middle of the room it does that spin left then right in one spot. It's not a "wheel" problem as I can see bc it will move forward and dock normally if placed as few feet from the dock and clean/dock is pushed. So ....

1. If Clean is pushed when it's on the dock it will back up, pause, spin to the left, pause, spin right, pause, spin left, pause, etc2. Hand carried to center of room... it worked for a day but now same thing.... spin, pause, spin.3. When placed on the floor 5 feet from the dock and push Clean/dock it will act normal and move forward and dock itself.

I've removed the bottom plate and diligently cleaned the sensors with a damp rag, but that's been no help. What can it be?

There are no lights flashing indicating any failure at all. It looks normal, just doesn't "act" normal. I thought it was a senser, but it senses it should dock when I place it 5 feet away and press dock like I said before?!

OK, I just placed it across the room and pressed the Clean/dock. It began to appear normal, doing its thing and searching for the beam THEN until it bumped into something straight on (It had no problem with a side bump on the chair). After the straight on bump it ..,.backed up a few inches, spin left, backed up an inch, spin right. Never moving forward. So yes, sounds like the front bumper sensor. How can it be a failure if there are no lights telling me it is?

I'm not really sure why you're not getting the failure indication. Everything else seems to point to the fact that there is a bumper sensor issue. Other owners have reported that the Roomba seems to run fine until the bumper is activated then the same behaviour is performed that you have witnessed.

I'm afraid that the blasting of air is not going to resolve your bumper failure. The bumper sensors (2) are internal sealed units that seem to be suscepitable to electronic failure due to either defective diodes or poor electrical connection. Disassembly will be required to reach the circuit boards containing the diodes and soldering skills needed to remove and replace the components. Or, order the sensors from ProTechRobotics and replace the whole assembly.

I had the same exact behavior. Mine is a 4xx series but I imagine the 5xx hasn't changed significantly. There is a dirt sensors underneath the brushes that look like dark flat penny sized brass circle. It's the only metal piece under the brush. With a moist q-tip (I just used warm water), clean it off. That did the trick on mine each time it started running in circles. (I only had to do it twice in the ~2 years I've had it).

I wish it was that simple to fix. I ran to get one after reading your post, of course! lol But sadly no... he still is confused. I just emailed itobot.... maybe, just maybe my warrenty is still good?! I love this little guy, I sure do hope I can get him fixed or replaced.